diff --git a/package.json b/package.json
index b0d75e18..f651b594 100644
--- a/package.json
+++ b/package.json
@@ -24,7 +24,7 @@
   },
   "devDependencies": {
     "@babel/core": "^7.12.10",
-    "@polkadot/dev": "^0.60.23"
+    "@polkadot/dev": "^0.60.27"
   },
   "version": "2.0.2-12"
 }
diff --git a/packages/bytes-asmjs-crypto/src/data.ts b/packages/bytes-asmjs-crypto/src/data.ts
index d963c048..7beaa384 100644
--- a/packages/bytes-asmjs-crypto/src/data.ts
+++ b/packages/bytes-asmjs-crypto/src/data.ts
@@ -1,4 +1,4 @@
 // Copyright 2017-2020 @polkadot/bytes-asmjs-crypto authors & contributors
 // SPDX-License-Identifier: Apache-2.0
 
-export default null;
+export const asmJsInit = null;
diff --git a/packages/bytes-asmjs-crypto/src/empty.ts b/packages/bytes-asmjs-crypto/src/empty.ts
index d963c048..7beaa384 100644
--- a/packages/bytes-asmjs-crypto/src/empty.ts
+++ b/packages/bytes-asmjs-crypto/src/empty.ts
@@ -1,4 +1,4 @@
 // Copyright 2017-2020 @polkadot/bytes-asmjs-crypto authors & contributors
 // SPDX-License-Identifier: Apache-2.0
 
-export default null;
+export const asmJsInit = null;
diff --git a/packages/bytes-wasm-crypto/src/data.ts b/packages/bytes-wasm-crypto/src/data.ts
index bfd6acf9..b86ce514 100644
--- a/packages/bytes-wasm-crypto/src/data.ts
+++ b/packages/bytes-wasm-crypto/src/data.ts
@@ -1,4 +1,4 @@
 // Copyright 2017-2020 @polkadot/bytes-wasm-crypto authors & contributors
 // SPDX-License-Identifier: Apache-2.0
 
-export default null;
+export const wasmBytes = null;
diff --git a/packages/bytes-wasm-crypto/src/empty.ts b/packages/bytes-wasm-crypto/src/empty.ts
index bfd6acf9..b86ce514 100644
--- a/packages/bytes-wasm-crypto/src/empty.ts
+++ b/packages/bytes-wasm-crypto/src/empty.ts
@@ -1,4 +1,4 @@
 // Copyright 2017-2020 @polkadot/bytes-wasm-crypto authors & contributors
 // SPDX-License-Identifier: Apache-2.0
 
-export default null;
+export const wasmBytes = null;
diff --git a/packages/wasm-crypto/package.json b/packages/wasm-crypto/package.json
index 7cb48c84..0a46b244 100644
--- a/packages/wasm-crypto/package.json
+++ b/packages/wasm-crypto/package.json
@@ -9,9 +9,9 @@
     "@polkadot/bytes-wasm-crypto": "^2.0.2-12"
   },
   "devDependencies": {
-    "@polkadot/dev": "^0.60.23",
-    "@polkadot/util": "^4.2.2-11",
-    "@polkadot/x-randomvalues": "^4.2.2-11",
+    "@polkadot/dev": "^0.60.27",
+    "@polkadot/util": "^4.2.2-12",
+    "@polkadot/x-randomvalues": "^4.2.2-12",
     "override-require": "^1.1.1"
   },
   "peerDependencies": {
diff --git a/packages/wasm-crypto/src/index.ts b/packages/wasm-crypto/src/index.ts
index 79926375..0a1117b1 100644
--- a/packages/wasm-crypto/src/index.ts
+++ b/packages/wasm-crypto/src/index.ts
@@ -1,13 +1,13 @@
 // Copyright 2019-2020 @polkadot/wasm-crypto authors & contributors
 // SPDX-License-Identifier: Apache-2.0
 
-import asmFallback from '@polkadot/bytes-asmjs-crypto';
-import wasmBytes from '@polkadot/bytes-wasm-crypto';
+import { asmJsInit } from '@polkadot/bytes-asmjs-crypto';
+import { wasmBytes } from '@polkadot/bytes-wasm-crypto';
 
 import { allocString, allocU8a, getWasm, initWasm, resultString, resultU8a, withWasm } from './bridge';
 import * as imports from './imports';
 
-const wasmPromise = initWasm(wasmBytes, asmFallback, imports).catch(() => null);
+const wasmPromise = initWasm(wasmBytes, asmJsInit, imports).catch(() => null);
 
 export const bip39Generate = withWasm((wasm) =>
   (words: 12 | 15 | 18 | 21 | 24): string => {
diff --git a/scripts/build-wasm.sh b/scripts/build-wasm.sh
index ea5dbf7b..404bd229 100755
--- a/scripts/build-wasm.sh
+++ b/scripts/build-wasm.sh
@@ -40,7 +40,8 @@ echo "*** Building asm.js version"
 sed -i -e '/import {/d' $ASM
 sed -i -e '/export var /d' $ASM
 sed -i -e 's/{abort.*},memasmFunc/wbg, memasmFunc/g' $ASM
-sed -i -e 's/var retasmFunc = /module.exports = (wbg) => /' $ASM
+sed -i -e 's/var retasmFunc = /const asmJsInit = (wbg) => /' $ASM
+echo "module.exports = { asmJsInit };" >> $ASM
 
 # cleanups
 rm -rf bytes-asmjs-crypto/build/*-e
diff --git a/scripts/pack-wasm-base.js b/scripts/pack-wasm-base.js
index 1aa6f158..31dd735f 100755
--- a/scripts/pack-wasm-base.js
+++ b/scripts/pack-wasm-base.js
@@ -12,19 +12,14 @@ const hdr = (package) => `// Copyright 2019-2020 @polkadot/${package} authors &
 // Generated as part of the build, do not edit
 `;
 
-function writeEsm (package) {
-  fs.writeFileSync(`./${package}/build/data.mjs`, `${hdr(package)}
-import data from './data.js';
-export default data;
+fs.writeFileSync(`./${A_NAME}/build/data.mjs`, `${hdr(A_NAME)}
+export { asmJsInit } from './data.js';
 `);
-  fs.writeFileSync(`./${package}/build/empty.mjs`, `${hdr(package)}
-export default null;
-`);
-}
 
-writeEsm(A_NAME);
-writeEsm(W_NAME);
+fs.writeFileSync(`./${W_NAME}/build/data.mjs`, `${hdr(W_NAME)}
+export { wasmBytes } from './data.js';
+`);
 
 fs.writeFileSync('./bytes-wasm-crypto/build/data.js', `${hdr(W_NAME)}
-module.exports = Buffer.from('${fs.readFileSync('./bytes/wasm_opt.wasm').toString('base64')}', 'base64');
+module.exports = { wasmBytes: Buffer.from('${fs.readFileSync('./bytes/wasm_opt.wasm').toString('base64')}', 'base64') };
 `);
diff --git a/yarn.lock b/yarn.lock
index 749a883d..87588a90 100644
--- a/yarn.lock
+++ b/yarn.lock
@@ -1702,9 +1702,9 @@ __metadata:
   languageName: unknown
   linkType: soft
 
-"@polkadot/dev@npm:^0.60.23":
-  version: 0.60.23
-  resolution: "@polkadot/dev@npm:0.60.23"
+"@polkadot/dev@npm:^0.60.27":
+  version: 0.60.27
+  resolution: "@polkadot/dev@npm:0.60.27"
   dependencies:
     "@babel/cli": ^7.12.10
     "@babel/core": ^7.12.10
@@ -1792,22 +1792,22 @@ __metadata:
     polkadot-exec-typedoc: scripts/polkadot-exec-typedoc.cjs
     polkadot-exec-vuepress: scripts/polkadot-exec-vuepress.cjs
     polkadot-exec-webpack: scripts/polkadot-exec-webpack.cjs
-  checksum: e6d1d95ea6dbc6713344f776b9638cea7c649fb56a4713d4c7f579ba0e918937a679e7dd65f09f6cf44da363767ed5a1c7689646043721c317cacfe880e66ed1
+  checksum: e4e90914eed69bd21f6617265030388e4d651046e156717a816e5a4719b75abbb5641e71025d2df1a71e45265b0fcadd201450e4b4ae67abf9b56dc029a2bb65
   languageName: node
   linkType: hard
 
-"@polkadot/util@npm:^4.2.2-11":
-  version: 4.2.2-11
-  resolution: "@polkadot/util@npm:4.2.2-11"
+"@polkadot/util@npm:^4.2.2-12":
+  version: 4.2.2-12
+  resolution: "@polkadot/util@npm:4.2.2-12"
   dependencies:
     "@babel/runtime": ^7.12.5
-    "@polkadot/x-textdecoder": 4.2.2-11
-    "@polkadot/x-textencoder": 4.2.2-11
+    "@polkadot/x-textdecoder": 4.2.2-12
+    "@polkadot/x-textencoder": 4.2.2-12
     "@types/bn.js": ^4.11.6
     bn.js: ^4.11.9
     camelcase: ^5.3.1
     ip-regex: ^4.2.0
-  checksum: 4206b48d7c93bf9a008211dd895321517213204fad3af1313c4a0c2eb88434f7ff1c577fa6f193b1e8ceddce0b5713dd97b4a2e630c271e30b66d299148890b3
+  checksum: 92a5cf2206a26382c44ec22d15b2cb30b1ee2a6e82bdd92106a7e6e67ceeedd1c743bc5e9ae9a5abd6569bf0f56272a479b058a5059bb3ab8774b6d9af831bed
   languageName: node
   linkType: hard
 
@@ -1818,9 +1818,9 @@ __metadata:
     "@babel/runtime": ^7.12.5
     "@polkadot/bytes-asmjs-crypto": ^2.0.2-12
     "@polkadot/bytes-wasm-crypto": ^2.0.2-12
-    "@polkadot/dev": ^0.60.23
-    "@polkadot/util": ^4.2.2-11
-    "@polkadot/x-randomvalues": ^4.2.2-11
+    "@polkadot/dev": ^0.60.27
+    "@polkadot/util": ^4.2.2-12
+    "@polkadot/x-randomvalues": ^4.2.2-12
     override-require: ^1.1.1
   peerDependencies:
     "@polkadot/util": "*"
@@ -1828,30 +1828,30 @@ __metadata:
   languageName: unknown
   linkType: soft
 
-"@polkadot/x-randomvalues@npm:^4.2.2-11":
-  version: 4.2.2-11
-  resolution: "@polkadot/x-randomvalues@npm:4.2.2-11"
+"@polkadot/x-randomvalues@npm:^4.2.2-12":
+  version: 4.2.2-12
+  resolution: "@polkadot/x-randomvalues@npm:4.2.2-12"
   dependencies:
     "@babel/runtime": ^7.12.5
-  checksum: 5ddf5204d46d2c5c4b8537b643791759a9022aae75fa8b409a07e6a008969dea09465ce11c6bd02db97c0a499808e5f2100cf2640fc211b5eb1dcb5665e7ec99
+  checksum: ca429802969f82bb6749d98b739d4ceca32b63d73cbdb615bfc777294096cdf78ac32e2f844e35f2ab52e8944e435fe7efabec9e88026a49a34de29cec424c1d
   languageName: node
   linkType: hard
 
-"@polkadot/x-textdecoder@npm:4.2.2-11":
-  version: 4.2.2-11
-  resolution: "@polkadot/x-textdecoder@npm:4.2.2-11"
+"@polkadot/x-textdecoder@npm:4.2.2-12":
+  version: 4.2.2-12
+  resolution: "@polkadot/x-textdecoder@npm:4.2.2-12"
   dependencies:
     "@babel/runtime": ^7.12.5
-  checksum: 6b82fcff43b0bc8cfe5ac0d5036147d1ea6efaef242951856f8c6d84329693037c83510f6576a354ff51c543339601318ddc79adade91a21e06bf19337a43b67
+  checksum: 41d9329082cef36c09f5955b4d6a299c8bbea20da197b1f60c8554a4cfc98b7d5ba4f69f56e23567904e07c4dd0a8a6862424c10d236933bc0574bce08c024d9
   languageName: node
   linkType: hard
 
-"@polkadot/x-textencoder@npm:4.2.2-11":
-  version: 4.2.2-11
-  resolution: "@polkadot/x-textencoder@npm:4.2.2-11"
+"@polkadot/x-textencoder@npm:4.2.2-12":
+  version: 4.2.2-12
+  resolution: "@polkadot/x-textencoder@npm:4.2.2-12"
   dependencies:
     "@babel/runtime": ^7.12.5
-  checksum: 9836879d73078a3ff0e7ad68f42dd4d8613b830cb4dfb727168cf206e12faf82305a3043028f54bd244008c92cd2e65f1ca89170bc6c9ed5b38a0408eea37735
+  checksum: 69c1a25e912d22d668f74bc03db13fb05e4bfe42ece3da958f0f29b3046288b361d6bbbf9aed3b7a29f10d805f649b99c6cb8469facd65b73433555cba56c931
   languageName: node
   linkType: hard
 
@@ -8560,7 +8560,7 @@ fsevents@~2.1.2:
   resolution: "root-workspace-0b6124@workspace:."
   dependencies:
     "@babel/core": ^7.12.10
-    "@polkadot/dev": ^0.60.23
+    "@polkadot/dev": ^0.60.27
   languageName: unknown
   linkType: soft